<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>新的字体单位 rem </title>
    <style>
        html {
            font-size: 12px;
        }

        body {
            font-size: 1.4rem;
        }

        h1 {
            font-size: 2.4rem;
        }
    </style>
</head>
<body>
    <div>Hello Panda</div>
    <h1>Hello Panda</h1>
</body>
</html>